[PATCH v8 04/10] drivers: qcom: rpmh: add RPMH helper functions

From: Lina Iyer
Date: Wed May 09 2018 - 13:04:03 EST


Sending RPMH requests and waiting for response from the controller
through a callback is common functionality across all platform drivers.
To simplify drivers, add a library functions to create RPMH client and
send resource state requests.

rpmh_write() is a synchronous blocking call that can be used to send
active state requests.

Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
---

Changes in v7:
- Optimization and locking fixes

Changes in v6:
- replace rpmh_client with device
- inline wait_for_tx_done()

Changes in v4:
- use const struct tcs_cmd in API
- remove wait count from this patch
- changed -EFAULT to -EINVAL
---
drivers/soc/qcom/Makefile | 4 +-
drivers/soc/qcom/rpmh-internal.h | 6 ++
drivers/soc/qcom/rpmh-rsc.c | 8 ++
drivers/soc/qcom/rpmh.c | 176 +++++++++++++++++++++++++++++++
include/soc/qcom/rpmh.h | 25 +++++
5 files changed, 218 insertions(+), 1 deletion(-)
create mode 100644 drivers/soc/qcom/rpmh.c
create mode 100644 include/soc/qcom/rpmh.h

diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index cb6300f6a8e9..bb395c3202ca 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -7,7 +7,9 @@ obj-$(CONFIG_QCOM_PM) += spm.o
obj-$(CONFIG_QCOM_QMI_HELPERS) += qmi_helpers.o
qmi_helpers-y += qmi_encdec.o qmi_interface.o
obj-$(CONFIG_QCOM_RMTFS_MEM) += rmtfs_mem.o
-obj-$(CONFIG_QCOM_RPMH) += rpmh-rsc.o
+obj-$(CONFIG_QCOM_RPMH) += qcom_rpmh.o
+qcom_rpmh-y += rpmh-rsc.o
+qcom_rpmh-y += rpmh.o
obj-$(CONFIG_QCOM_SMD_RPM) += smd-rpm.o
obj-$(CONFIG_QCOM_SMEM) += smem.o
obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h
index cc29176f1303..d9a21726e568 100644
--- a/drivers/soc/qcom/rpmh-internal.h
+++ b/drivers/soc/qcom/rpmh-internal.h
@@ -14,6 +14,7 @@
#define MAX_CMDS_PER_TCS 16
#define MAX_TCS_PER_TYPE 3
#define MAX_TCS_NR (MAX_TCS_PER_TYPE * TCS_TYPE_NR)
+#define RPMH_MAX_CTRLR 2

struct rsc_drv;

@@ -52,6 +53,7 @@ struct tcs_group {
* @tcs: TCS groups
* @tcs_in_use: s/w state of the TCS
* @lock: synchronize state of the controller
+ * @list: element in list of drv
*/
struct rsc_drv {
const char *name;
@@ -61,9 +63,13 @@ struct rsc_drv {
struct tcs_group tcs[TCS_TYPE_NR];
DECLARE_BITMAP(tcs_in_use, MAX_TCS_NR);
spinlock_t lock;
+ struct list_head list;
};

+extern struct list_head rsc_drv_list;

int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg);

+void rpmh_tx_done(const struct tcs_request *msg, int r);
+
#endif /* __RPM_INTERNAL_H__ */
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index 0a8cec9d1651..c0edf3850147 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -61,6 +61,8 @@
#define CMD_STATUS_ISSUED BIT(8)
#define CMD_STATUS_COMPL BIT(16)

+LIST_HEAD(rsc_drv_list);
+
static u32 read_tcs_reg(struct rsc_drv *drv, int reg, int tcs_id, int cmd_id)
{
return readl_relaxed(drv->tcs_base + reg + RSC_DRV_TCS_OFFSET * tcs_id +
@@ -176,6 +178,8 @@ static irqreturn_t tcs_tx_done(int irq, void *p)
spin_lock(&drv->lock);
clear_bit(i, drv->tcs_in_use);
spin_unlock(&drv->lock);
+ if (req)
+ rpmh_tx_done(req, err);
}

return IRQ_HANDLED;
@@ -469,6 +473,10 @@ static int rpmh_rsc_probe(struct platform_device *pdev)
/* Enable the active TCS to send requests immediately */
write_tcs_reg(drv, RSC_DRV_IRQ_ENABLE, 0, drv->tcs[ACTIVE_TCS].mask);

+ INIT_LIST_HEAD(&drv->list);
+ list_add(&drv->list, &rsc_drv_list);
+ dev_set_drvdata(&pdev->dev, drv);
+
return devm_of_platform_populate(&pdev->dev);
}

diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
new file mode 100644
index 000000000000..74bb82339b01
--- /dev/null
+++ b/drivers/soc/qcom/rpmh.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/atomic.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+#include <soc/qcom/rpmh.h>
+
+#include "rpmh-internal.h"
+
+#define RPMH_TIMEOUT_MS msecs_to_jiffies(10000)
+
+#define DEFINE_RPMH_MSG_ONSTACK(dev, s, q, name) \
+ struct rpmh_request name = { \
+ .msg = { \
+ .state = s, \
+ .cmds = name.cmd, \
+ .num_cmds = 0, \
+ .wait_for_compl = true, \
+ }, \
+ .cmd = { { 0 } }, \
+ .completion = q, \
+ .dev = dev, \
+ }
+
+/**
+ * struct rpmh_request: the message to be sent to rpmh-rsc
+ *
+ * @msg: the request
+ * @cmd: the payload that will be part of the @msg
+ * @completion: triggered when request is done
+ * @dev: the device making the request
+ * @err: err return from the controller
+ */
+struct rpmh_request {
+ struct tcs_request msg;
+ struct tcs_cmd cmd[MAX_RPMH_PAYLOAD];
+ struct completion *completion;
+ const struct device *dev;
+ int err;
+};
+
+/**
+ * struct rpmh_ctrlr: our representation of the controller
+ *
+ * @drv: the controller instance
+ */
+struct rpmh_ctrlr {
+ struct rsc_drv *drv;
+};
+
+static struct rpmh_ctrlr rpmh_rsc[RPMH_MAX_CTRLR];
+static DEFINE_SPINLOCK(rpmh_rsc_lock);
+
+static struct rpmh_ctrlr *get_rpmh_ctrlr(const struct device *dev)
+{
+ int i;
+ struct rsc_drv *p, *drv = dev_get_drvdata(dev->parent);
+ struct rpmh_ctrlr *ctrlr = ERR_PTR(-EINVAL);
+ unsigned long flags;
+
+ if (!drv)
+ return ctrlr;
+
+ for (i = 0; i < RPMH_MAX_CTRLR; i++) {
+ if (rpmh_rsc[i].drv == drv) {
+ ctrlr = &rpmh_rsc[i];
+ return ctrlr;
+ }
+ }
+
+ spin_lock_irqsave(&rpmh_rsc_lock, flags);
+ list_for_each_entry(p, &rsc_drv_list, list) {
+ if (drv == p) {
+ for (i = 0; i < RPMH_MAX_CTRLR; i++) {
+ if (!rpmh_rsc[i].drv)
+ break;
+ }
+ if (i == RPMH_MAX_CTRLR) {
+ ctrlr = ERR_PTR(-ENOMEM);
+ break;
+ }
+ rpmh_rsc[i].drv = drv;
+ ctrlr = &rpmh_rsc[i];
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&rpmh_rsc_lock, flags);
+
+ return ctrlr;
+}
+
+void rpmh_tx_done(const struct tcs_request *msg, int r)
+{
+ struct rpmh_request *rpm_msg = container_of(msg, struct rpmh_request,
+ msg);
+ struct completion *compl = rpm_msg->completion;
+
+ rpm_msg->err = r;
+
+ if (r)
+ dev_err(rpm_msg->dev, "RPMH TX fail in msg addr=%#x, err=%d\n",
+ rpm_msg->msg.cmds[0].addr, r);
+
+ /* Signal the blocking thread we are done */
+ if (compl)
+ complete(compl);
+}
+EXPORT_SYMBOL(rpmh_tx_done);
+
+/**
+ * __rpmh_write: send the RPMH request
+ *
+ * @dev: The device making the request
+ * @state: Active/Sleep request type
+ * @rpm_msg: The data that needs to be sent (cmds).
+ */
+static int __rpmh_write(const struct device *dev, enum rpmh_state state,
+ struct rpmh_request *rpm_msg)
+{
+ struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
+
+ if (IS_ERR(ctrlr))
+ return PTR_ERR(ctrlr);
+
+ rpm_msg->msg.state = state;
+
+ if (state != RPMH_ACTIVE_ONLY_STATE)
+ return -EINVAL;
+
+ WARN_ON(irqs_disabled());
+
+ return rpmh_rsc_send_data(ctrlr->drv, &rpm_msg->msg);
+}
+
+/**
+ * rpmh_write: Write a set of RPMH commands and block until response
+ *
+ * @rc: The RPMH handle got from rpmh_get_client
+ * @state: Active/sleep set
+ * @cmd: The payload data
+ * @n: The number of elements in @cmd
+ *
+ * May sleep. Do not call from atomic contexts.
+ */
+int rpmh_write(const struct device *dev, enum rpmh_state state,
+ const struct tcs_cmd *cmd, u32 n)
+{
+ DECLARE_COMPLETION_ONSTACK(compl);
+ DEFINE_RPMH_MSG_ONSTACK(dev, state, &compl, rpm_msg);
+ int ret;
+
+ if (!cmd || !n || n > MAX_RPMH_PAYLOAD)
+ return -EINVAL;
+
+ memcpy(rpm_msg.cmd, cmd, n * sizeof(*cmd));
+ rpm_msg.msg.num_cmds = n;
+
+ ret = __rpmh_write(dev, state, &rpm_msg);
+ if (ret)
+ return ret;
+
+ ret = wait_for_completion_timeout(&compl, RPMH_TIMEOUT_MS);
+ return (ret > 0) ? 0 : -ETIMEDOUT;
+}
+EXPORT_SYMBOL(rpmh_write);
diff --git a/include/soc/qcom/rpmh.h b/include/soc/qcom/rpmh.h
new file mode 100644
index 000000000000..c1d0f902bd71
--- /dev/null
+++ b/include/soc/qcom/rpmh.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef __SOC_QCOM_RPMH_H__
+#define __SOC_QCOM_RPMH_H__
+
+#include <soc/qcom/tcs.h>
+#include <linux/platform_device.h>
+
+
+#if IS_ENABLED(CONFIG_QCOM_RPMH)
+int rpmh_write(const struct device *dev, enum rpmh_state state,
+ const struct tcs_cmd *cmd, u32 n);
+
+#else
+
+static inline int rpmh_write(const struct device *dev, enum rpmh_state state,
+ const struct tcs_cmd *cmd, u32 n)
+{ return -ENODEV; }
+
+#endif /* CONFIG_QCOM_RPMH */
+
+#endif /* __SOC_QCOM_RPMH_H__ */
--
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